This application discloses an invention which is related, generally and in various embodiments, to a bead lock which is configured to provide protection to the wheel flanges when a tire mounted on the wheel is operated at a low tire pressure.
In applications where a tire of a vehicle is intentionally operated at a lower than normal tire pressure, the tire beads may become separated from one or both wheel flanges. If a tire bead becomes separated from a wheel flange, the air pressure in the tire can quickly escape to the atmosphere, leading to substantial and/or total deflation of the tire. With a tire substantially and/or totally deflated, the wheel flanges are basically forced to carry the portion of the vehicle's weight normally carried by the inflated tire, which in turn is supported by the wheel through the standardized tire-wheel interface geometry. When this condition arises, significant damage to one or both wheel flanges is typically incurred. In some situations, the vehicle can even be rendered immobile. In any event, the damaged wheels often need to be replaced in order for the vehicle to maintain its expected performance. The cost and the downtime associated with replacing the wheels can be significant.
For many off-road and military applications, where the tires can experience high lateral forces, be sliced or punctured by sharp or jagged objects, be subjected to a ballistic event, etc., it is far too common for the tires to become substantially and/or totally deflated, leading to the tire beads separating from the wheel flanges and subsequent damage to the wheel flanges.
It is a known and established method to utilize bead locks installed inside the cavity of a tire mounted on a wheel in order to keep the beads of a tire secured against the flanges of the wheel. Such an internal bead lock is used to apply lateral pressure on the tire beads to secure and in a sense “lock” them to the bead-seat and flange areas of the wheel flange. By locking the tire beads to the wheel flanges, a tire can be operated at lower than normal tire pressures in order to increase the tire ground contact patch and thus increase tire traction and flotation, with less risk of the tire beads separating from the wheel flanges (de-seating) and the tire rapidly deflating. Additionally, having a tire locked to the wheel flanges allows the vehicle to operate at lower than normal tire pressures in extreme torque transfer situations (e.g., situations involving an incline, a decline, rapid acceleration and deceleration, etc.) without the tire slipping or spinning on the wheel.
FIG. 1 illustrates a known bead lock. This bead lock, commonly known as an internal metal bead lock, includes an annular shaped metal piece and two rubber or elastomer pieces. The annular shaped metal piece is configured to have its two “ends” connected together to form a ring. The two rubber or elastomer pieces are positioned over the respective “edges” of the metal pieces. FIG. 2 illustrates a cross section of the bead lock of FIG. 1 installed in a cavity of a tire mounted on a wheel. As shown in FIG. 2, the rubber or elastomer pieces are the components of the bead lock which are in contact with the “interior” surface of the tire, and the “exterior” surface of the tire is in contact with the wheel flanges.
FIG. 3 illustrates another known bead lock. This bead lock, known as an internal rubber bead lock, is an annularly shaped “band” of rubber. FIG. 4 illustrates a cross-section of the bead lock of FIG. 3 installed in a cavity of a tire mounted on a wheel. As shown in FIG. 4, the respective “edges” of the bead lock are in contact with the “interior” surface of the tire, and the “exterior” surface of the tire is in contact with the wheel flanges.
Current bead locks do not adequately prevent damage inflicted on the wheel flanges, can result in the vehicle being rendered immobile due to the damaged wheels, and do not adequately contribute to the avoidance of the cost and downtime associated with having to replace the damaged wheels.